trac-admin /path/to/trac wiki export <wiki page name>

import os
import xmlrpc.client
import getpass
import urllib.parse


def add_auth(url):
    host = urllib.parse.urlparse(url).netloc
    realm = os.environ.get('TRAC_REALM', host)
    username = getpass.getuser()
    try:
        import keyring
        password = keyring.get_password(realm, username)
    except Exception:
        password = getpass.getpass(f"password for {username}@{realm}: ")

    if password:
        url = url.replace('://', f'://{username}:{password}@')

    return url


def main():
    trac_url = add_auth(os.environ['TRAC_URL'])
    rpc_url = urllib.parse.urljoin(trac_url, 'login/xmlrpc')
    trac = xmlrpc.client.ServerProxy(rpc_url)

    for page in trac.wiki.getAllPages():
        filename = f'{page}.html'.lstrip('/')
        dir = os.path.dirname(filename)
        dir and os.makedirs(dir, exist_ok=True)
        with open(filename, 'w') as f:
            doc = trac.wiki.getPageHTML(page)
            f.write(doc)


__name__ == '__main__' and main()

$ TRAC_URL=http://mytrac.mydomain.com python3.6 export-wiki.py